Air heating apparatus



Dec. 8, 1959 J. A. KITCHEN V AIR HEATING APPARATUS Filed oct. 1o,` 19572 Sheets-Sheet l Deer. 8, 1959 J. A. KITCHEN 2,916,032

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I O E I`- ooo l O" "T ooo O N o o o I- J S \7 Flgz E I United States iPatent AJR HEATING APPARATUS John A. Kitchen, Markham, Ontario, Canada,assignon by mesne assignments, to Lucas-Rotax Limited, Ontario, CanadaApplication October 10, 1957, Serial No. 689,438

Claims priority, application Great Britain October 11, 1956 1 Claim.(Cl. 126-116) This invention has for its object to provide in an eicientand compact form, an apparatus for heating air to be used forroom-warming or other purposes.

An apparatus in accordance with the invention comprises a gaseous orliquid fuel combustion chamber, a tubular heat exchanger in directconnection with the combustion chamber, a chest on one side of which thecombustion chamber and heat exchanger are mounted, and fuel andcombustion-air supply means contained in the chest, the arrangementbeing such that the chest can be mounted over an aperture in one side ofan air duct with the combustion chamber and heat exchanger extendinginto the duct.

In the accompanying drawings, Figures 1 and 2 are sectional sideelevations in planes which are mutually at right angles, of an apparatusembodying the invention and adapted for combustion of gaseous fuel,Figure 1 being taken on the line 1-1 of Figure 2.

In the example illustrated by the drawings, the combustion chamber aconsists of a hollow metal casting having air-heating fins b extendingfrom its outer surface. Parallel and in communication with thecombustion chamber is formed or connected an exhaust gas manifold c, andto this manifold is connected the heat exchanger. The latter comprises aplurality of tubes d each bent to a zig-zag form and having fiatheat-trans mitting metal plates e combined therewith. The tubes andplates are arranged parallel with each other in planes parallel with thedirection of ow of the air to be heated. At one end the tubes areattached to the above mentioned monifold c. At their other ends they areconnected to another exhaust gas manifold f.

The combustion chamber and heat exchanger are mounted on one side of achest g which is divided by partitions g to form a plurality of separatecompartments. In the compartment h is contained a fuel gas reservoirwhich is supplied through a pipe j under the control of any convenientvalve j', a box k which contains electrical ignition apparatus forproducing sparks at a sparking gap m in the combustion chamber, an airsupply fan n and an electric motor o for driving the fan. Air isconveyed from the outer atmosphere to the compartment h through aperforated pipe p contained in a second compartment q situated alongsidethe first compartment, this pipe surving to muiie the sound of theingoing air.

A third compartment r in the chest situated beneath the iirst mentionedcompartment has connected to it the second manifold f above mentioned,and this compartment serves as an exhaust gas cushion. This compartmentis also provided at its lower part with a drain s,

through which condensation can be discharged. A fourth compartment tsituated alongside the first compartment contains another perforatedpipe u which conveys the exhaust gases from the third compartment to theatmosphere, this pipe serving as an exhaust gas muier.

The combustion apparatus is of the so-called pulsatory type. The fuelgas is admitted from the reservoir i to the combustion chamber through afreely movable valve v, and the air is admitted from the compartment hthrough a similar valve w. Preferably the gas and air are mixed beforeentering the combustion chamber in an antechamber x which is separatedfrom the combustion chamber by a llame trap y. With ignition of themixture in the combustion chamber, the eiect of the rise of pressure inthis chamber is to close the valves v, w. When this pressure falls belowthat of the gas in the reservoir i and air in the compartment h thevalves reopen and allow a further quantity of gas and air to pass,combustion being maintained by continued intermittent supplies of gasand air in known manner.

The arrangement is such that the chest g can be secured through themedium of flanges g2 on the exterior of a wall forming one side of aduct z along which flows the air to be heated, with the combustionchamber and heat exchanger extending through an aperture in the wallinto the duct. When the apparatus is in use, the air first flows overthe heat exchanger, and then over the combustion chamber, from both ofwhich parts it receives the required heat. From the air duct the heatedair is distributed through other ducts to the rooms to be warmed.

The apparatus above described is adapted for combustion of gaseous fuel.The invention is not however restricted to such use, as it may beadapted to utilise a liquid fuel by employing any conventional means forvaporising or nebulising the fuel, such as a carburetor, heatedvaporiser, or spraying nozzle.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

An apparatus for heating air flowing through an air duct, comprising incombination with an elongated combustion chamber of the pulsatory typehaving at one end pressure-responsive inlet Valves by which fuel andcombustion-air under pressure are admissible to said combustion chamber,and which are arranged to be opened by the pressures of the fuel andcombustion-air, and to be closed by the pressure of combustion withinsaid combustion chamber, an elongated exhaust gas manifold communicatingwith said combustion chamber 'and situated at one side thereof inparallel relationship therewith, a second exhaust gas manifold spacedfrom the first mentioned manifold, a tubular heat exchangerinterconnecting the two manifolds, a chest on one side of which saidcombustion chamber, exhaust gas manifolds, and heat exchanger aremounted, and which is provided with means whereby said chest can besecured over an aperture in one side of the air duct with said chestoutside the duct, and with said combustion chamber, exhaust gasmanifolds, and heat exchanger within the duct, partitions dividing theinterior of said chest into four compartments, fuel and combustion-airsupply means which are mounted in a rst compartment of said chest, andfrom which fuel and combustion-air have Patented Dec. 8, 1.95.9 n

rchest'to' conveyexhas't'gas to the outer atmosphere and to serve as anexhaust gas muer.

References Cited in the file of this patent UNITED STATES PATENTSMueller Nov. 18, 1941 Frantz Dec. 30, 1941 May 12, 1953 Jaye et a1. -;LNov. 10,1953V

